Electric switch



Dec. 26, 1950 J. M. TYRNER 2,535,556

ELECTRIC SWITCH Filed Sept. 6, 1946 2 Sheets-Sheet 2 IVVENTOIL Patented Dec. 26, 1950 ELECTRIC SWITCH Joseph M. Tyrner, New York, N. Y., assignor to Air Reduction Company, Incorporated, a corporation of New York Application September 6, 1946, Serial No. 695,201

2 Claims.

This invention relates to electric switches and, more particularly. to improvements in electromagnetic switches, the principal feature of the invention being the provision of improved means for providing an air blast to extinguish promptly any arc'that might be drawn between the switch contacts. I

In general, my improved switch mechanism comprises a central operating plunger carrying a contactbridge plate adapted to engage a pair of stationary contacts to complete an electric circuit from one stationary contact to the other. The operating plunger also carries a piston plate disposed in an air chamber or cylinder, the arrangement being such that when the switch solenoid is deenergized, the operating plunger is released to move the contact bridge member away from the pair of stationary contacts and to simultaneously move the piston plate to cause a blast of air to pass between the stationary and movable switch elements to extinguish any arc that might be drawn between the switch contacts as they are separated.

A preferred embodiment of my invention comprises a unitary structure including an air chamber or cylinder containing the piston plate, and a second chamber enclosin the switch contacts. These chambers are formed in such a manner that they communicate with each other so that as the switch operates to close the switch contacts, air is drawn into the air cylinder and so that as the switch mechanism operates to open the contacts, air is forced from the air chamher into the switch contact chamber to produce a blast of air between the switch contacts as.

they are separated.

The construction of my improved switch mechanism is such that any desired number of pairs of stationary switch contacts and cooperating bridge contact plates may be assembled in superimposed relation to provide what is in effect a gang switch for controlling a plurality of electric circuits.

The various objects and advantages of my invention will be more apparent upon considering the following detailed description of certain typical embodiments thereof illustrated in the accompanying drawings, in which Fig. 1 is an elevation, partly in section, of an electromagnetic switch embodying my invention showing the switch open, i. e.. with the switch contacts separated;

Fig. 2 is an elevation, partly in section, illustrating the switch mechanism of Fig. 1 with the switch contacts in closed position;

Fig. 3 is a partial transverse section view taken on line 3-3 of Fig. 1;

Fig. 4 is a fragmentary vertical section view of a modified form of the switch mechanism embodying my invention; and

Fig. 5 is a vertical section view of the mechanism illustrated in Fig. 4 taken at right angles to Fig. 4.

The illustrative embodiment of my invention illustrated in Figs. 1-3, inclusive, comprises an electromagnetic switch having an operating solenoid I having a stationary laminated field member 2 and a movable core 3 adapted to actuate the switch mechanism hereinafter described. This movable core member 3 carries a switch operating plunger comprising. a central bolt 4 having its screw threads engaging a threaded opening in the lower part of the core 3. The head of the bolt 4 engages a cup-shaped member 5, preferably of insulating material, containing a coil spring 6 and having a central sleeve 1 en aging the lower end of an insulating spacer 8 which in turn engages a piston plate 9. The upper surface of this piston plate 9 engages another insulating spacer l0 and it will be under stood that when the central bolt 4 is tightened, the central sleeve 1 of the cup-shaped member 5, the spacer members 8 and Ill and the piston plate 9 are all firmly clamped together to form a unit firmly secured to the movable core member 3 by the bolt 4.

The coil spring 8 in the cup-shaped member 5 engages the lower surPace of a bridge plate ll carrying electrical contacts I! at its extremities adapted to engage a pair of stationary contacts I3. It will be understood that Figs. 1-3, inclusive, are partial section views illustrating only one stationary contact l3 and one contact I! carried by the bridge plate H, the other pair of relatively movable contacts being located in that portion of the contact chamber which is not shown in section. This contact chamber is formed by a body ll of molded insulation or the like having a central partition l5 dividing the space inside this body into two parts, the lower portion forming what may be characterized as a switch contact chamber and the upper porthe switch chamber may be formed of one or more pieces of insulating material as desired, and this body is secured to a supporting plate I! by through bolts l9 and 20. These bolts I9 and 20. also engage flanges forming'a part of a support 2| carrying the solenoid structure 5.

When current is supplied to the solenoid 8 (through suitable circuit leads not illustrated), the movable core 3 of magnetic material is attracted by the stationary field element 2 and the central operating plunger comprising the bolt 4 and the parts adjacent thereto move upward carrying the bridge contact plate El upward to bring the contacts it into engagement with the stationary contacts i3. As this movement occurs, the piston plate 9 is carried upward to draw air into the air chamber in which this plate is located, the air being drawn into this chamber through the ports il in the contact chamber wall and through the central aperture it interconnecting the upper and lower chambers in the structure. Fig. 2 shows this closed chamber where it produces a blast of air between the contacts 52 and is as they separate, the air being exhausted through the lateral ports W. The bridg'e plate ii is substantially coextensive with the width of the switch contact chamber as best illustrated in Fig. 8, and accordingly during the initial portion of the opening movement of the switch mechanism, the air forced out of the air chamber by the piston plate 8 is confined in a relatively small channel in the switch contact chamber, formed by the partition is and the bridge plate ii, thus insuring a rapid movement of the air between the contacts l2 and H as it is discharged toward the exhaust port i1. With the switch mechanism mounted in a vertical position as illustrated in Figs. 1 and 2, the weight of the core 3 and the parts carried thereby is sumcient to cause rapid opening of the switch contacts and the production of a strong blast of air between these contacts as they are separated. If desired, a spring may be employed for accelerating this movement of the switch mechanism.

The stationary contacts l3 are carried by metal strips 22 which extend through the wall of the housing H. These metal strips are welded or otherwise secured to terminals 23 having set screws 24, by means of which leads connected to an external circuit may be firmly secured. to the switch mechanism in electrical contact with con ducting strips 22 carrying the stationary contacts iii.

The structure illustrated in Figs. 1-3, inclusive, includes a single pair of stationary contacts l3 and a single contact bridge plate II, but it will be understood that the switch mechanism may control several circuits by employing additional housing elements [4 and additional pairs of stationary contacts and cooperating bridge contact plates. In such instances, it is merely necessary to employ longer through bolts l9 and 20 and a longer central bolt 4 engaging the armature 3 of the electromagnet.

In Figs. 4 and 5, I have illustrated a modified form 01' switch mechanism employing a. different Figs. 1-3. In Figs. 4 and 5, the electromagnet comprises a field structure including a magnetizing cofl or solenoid 25 and a metal cover 2' secured to the supporting plate l8 by the bolts 89 and 20. The armature of the electromagnet is in the form of a magnetizable core 21 disposed within the solenoid 25. The central bolt 4 of the switch actuating member engages a screwthreaded opening at the base of the core 21 and in all other respects the apparatus illustrated in Figs. 4 and 5 may be the same as that illustrated in Figs. 1-3, inclusive.

The specific embodiments of my invention illustrated in the accompanying drawings are to be regarded as typical of electromagnetic switches embodying my invention which makes it possible to utilize simple, inexpensive parts which can be assembled with a minimumof labor to provide reliable switch mechanism including means for producing an air blast between the switch contacts as they are separated upon the opening of the switch to interrupt the flow of current in the circuit or circuits controlled by the switch apparatus. The air blast effectively curbs the arcing that would otherwise occur at the switch contacts. Switches made in accordance with my invention are capable of controlling several times as much current as the same size of switch would be capable of controlling without the air blast feature for blowing out the arc.

It is to be understood that my invention is not limited to the specific embodiments illustrated and described in detail, but includes such modifications thereof as fall within the scope of the appended claims.

I claim:

1. An electric switch comprising a housing having a partition therein whereby the housing provides an air chamber and a switch contact chamber, said partition having a central opening therein interconnecting said chambers, a pair of stationary contacts in said contact chamber, a

' movable contact bridge member in said contact chamber, a switch actuating member extending through the opening in said partition and connected to said bridge member, and a piston plate in said air chamber connected to said actuating member whereby operation of said actuating member to move the bridge member away from said contacts also moves the piston plate to force air out of the air chamber and into the contact chamber to provide a blast of air between the contacts and said bridge member, the said housing having ports'for accommodating the flow of air into and out of the contact chamber.

2. An electric switch comprising a support, an electromagnet having a field structure and a movable armature, the field structure being mounted on said support, a molded insulating housing detachably secured to said support be low the electromagnet, a partition within the housing dividing said housing into an air chamber and a switch contact chamber, said partition having a central opening placing the air chamber in communication with the switch con tact chamber, a pair of stationary contacts mounted in the air chamber on the partition, a switch actuating insulating member connected to the movable armature and depending therefrom through both chambers of the housing and the opening in the partition, a contact bridge member mounted in the switch contact chamber upon the switch actuating member andadapttype 01' electromagnet than that illustrated in 7a edtoconnect the stationary contacts whenmoved switch contact chamber having openings in' its -walls laterally opposite the stationary contacts 5 for permitting the flow of air into and out of said housing, whereby operation of the switch actuating member to move the contact bridge member away from the stationary contacts also moves the piston plate to force air from the air chamber through the partition opening, into the contact chamber, between the stationary contacts and the bridge member, and out of the housing through the housing ports.

JOSEPH M. TYRNER.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 608,134 Lundell July 26, 1898 2,266,982 Milliken Dec. 23, 1941 2,272,380 Ludwig et al. Feb. 10, 1942 2,430,008 Fernier Nov. 4, 1947 OTHER REFERENCES Ser. No. 287,348, Fernier (A. P. C.), pub. June 15, 1943. 

